Sewing machine



May 29, 1951 v R. cAsAs ROBERT SEWING MACHINE hum r0? Filed March 31, 1949 Patented May 29, 1951 SEWING MACHINE Ramon Casas Robert, Geneva, Switzerland, assignorto Mefina S. A., Binningen, Switzerland; a corporation of Switzerland Application March 31, 1949, Serial No. 84,602 In Switzerland December 20, 1948 Claims. 1

In a sewing machine, the thread feeding the needle passes first through a guide fixed at the end of an arm, then through a tension device before passing through the thread-puller, and finally through a. guide fixed to the needlecarrier.

In almost all known machines, the thread tension device is situated on the fore face of the needle-carrying arm, that is to say on the wall facing the operator. Now, practice has shown that the thread tension device is a source of great eye strain for the operator.

Indeed, this thread tension device intercepts the view of the operator watching the running of the work under the presser foot, and owing to the fact that this: tension device is vibrating all the time and is situated closer to the operators eye than the work, it constitutes a great hindrance, because the lower part of the presser foot is visible only to the operator's left eye. Thus the tension. device induces the operator to squint thereby provoking a great eye strain.

some designers. have endeavored to remedy this inconvenience by placing the tension device on the rear wall or on the: front face of the needle-carrying arm, but such an arrangement is a source of difficulties in construction and mechanical drawbacks which make. it preferable to place the tension device on the arms fore wall.

The present invention relates to a sewing machine including a column bearin an arm at the. end of which are mounted the needle-carrier and the thread-puller, both driven in a to-andfro movement by transmission members housed in said arm, the latter having on its rear face a support for a thread reel and a thread-guide which latter is located at the end of the arm, at the height of said support. This machine differs from the known machines in that it has means for safeguarding the thread over the full length ofits path between said guide and the thread-puller.

The attached drawing shows diagramatically and by way of example a form of construction of a sewing machine in accordance with the invention.

Fig. i is a view of' the end face of the needlecarrying arm;

Ftig. 2 is a perspective view of the front wall of the needle-carrying arm;

Fig. 3 is a perspective view of the rear wall of the needle-carrying arm Fig. 4 is a top view of the needle-carrying arm 5' is a part cross-section view along the line vv of the Fig. 1'.

Sewing machine represented on the drawing includes a column I bearing an arm 2 at the end of which is mounted a needle-carrier 3 and a thread-puller 4, both driven in a to-and-fro movement by a mechanism (which is not shown) housed in the arm and connected to a driving motor (not. represented) housed in the column. The rear face of the arms column has a flat surface 5 carrying two fixed spindles 6 and I intended to receive two spools 8 and 9. A threadguide it. is fixed on the rear wall of arm 2, at the end of the said arm,. approximately in the trans-versal middle plane of the reels.

The arm 2 has an end. face ll, provided with a protruding part 1.2, from which emerges laterally the thread-puller 4.. The end of the latter, in. its extreme upper position, is. approximately situated in a horizontal plane a, passing through the thread-guide ID.

The protruding part 12 has a general V-shape, with a rounded lower end. The front and rear surfaces of the v-shaped part I2 are connected at. their upper portions by a top wall l3 of semicylindrical form and aligned with the upper wall of the arm 2. The V formed by the protruding part I2 is symmetrically arranged in relation to a vertical longitudinal plane I): passing through the center of the arm 2, and the thread-puller and the thread-guide are symmetrically arranged on either side of this plane. Thus, seen from the end (Fig. 1) the arm has a very marked symmetry in relation to the plane I), which helps to impart to the sewing machine an elegant appearance pleasing to the eye.

The lower part of the protuberance 12 covers a tension device It, symmetrically arranged in relation to the plane b, and of which the axis of the shaft ['5 coincides with the axis of the bottom semi-cylindr cal wall' It forming the lower part of the V. This cylindrical wall has a slot ll' intended for the passage of the thread. The ends t8 and E9 of this slot are so shaped as to constitute guides for the thread, entering and leaving the tension device.

The slope of the rear and front walls 20 and 2| of the protuberance I2 is such that the threadguide land the end of the thread-puller in its extreme upper position are situated in line with said slopes; Thus, the portions of thread 6 and 1 run along these walls 26 and 2| close to the end face H of the arm (Fig; 5), so that the thread i's efiiciently' safeguarded against any accidental catching risking either damage to the thread, or hindrance to the proper working of the switch formation device.

In addition, the path followed by the end of the thread-puller is almost parallel to the front wall 2| of the protuberance l2, a slot 23 being provided in this wall to permit the movement of the thread-puller, The end of the threadpuller extends only in its extreme upper position beyond the cylindrical surface formed by the arm 2 in order to allow the passage of the thread,

but, as far as possible, in all its other positions I it is nearly concealed. An eyelet 24 is fixed to the lower part of wall 2! in order to keep the thread portion g, situated between the end of the thread-puller and this eyelet, close to the walls 2| and H. Thus, this portion g of the thread is also efficiently safeguarded against any accidental risks of damage to the sight of the operator watching the needles work. The result is, that with a sewing machine such as described with reference to the attached drawing, work is far less tiring for the operators eyes than with a machine of known type provided with a tension device arranged on the fore side of the needlecarrying arm.

Finally, also for the purpose of still safeguarding as far as possible, the portion of thread it situated between the reel and the thread-guide H), the latter is arranged parallel with and very close to the cylindrical surface of the arm 2, slightly below or almost at the height of the horizontal diametrical plane a.

From above description and by examining the attached drawing, one can realize the advantages offered by a sewing machine in accordance with the invention over a sewing machine of known type in which the thread is not safeguarded in any way and can therefore be caught inadvertently either by a ring worn by the operator, or by buttons on the work being done.

A form of construction of the machine in accordance with the invention has been described by way of example, but it is clear that slight variations in construction could be provided for, whilst remaining within the scope of the invention. Thus, it is not necessary for the protruding part l2 to be arranged symmetrically in relation to the vertical plane b. However, such an arrangement is advantageous from the point of view of appearance. One could also provide the protruding part with rims overhanging the walls 20 and 2|, so as to form with the end face I I two lateral grooves in which would be housed the portions of threads e, f and g, as well as the end of the thread-puller during the greatest part of its travelling.

I claim:

I l. A sewing machine including a column bearing an arm, a needle-carrier and a thread-puller mounted at the end of said arm and actuated in a to-and-fro movement, a spool support located on the rear wall of said arm and a thread-guide arranged at the end of said arm at the height of said spool support, a part protruding with respect to the end face of said arm disposed for safeguarding the full length of the thread path located between said guide and said thread-puller which merges laterally from said protruding part on the front of said arm, said thread-guide and the end of said thread-puller in its extreme position, being situated almost in a same horizontal plane and on either side and approximately at an even distance from a longitudinal middle plane of said a tension device for the thread covered by said protruding part, and a shaft for said tension device having its axis located in said longitudinal plane of sa d am,

said protruding part having front and rear walls and being of the general shape of a V of which the lower angle is rounded whereby the path of said thread from said guide to said end of the thread-puller in its upper position has the general shape of a V arranged symmetrically in relation to the said longitudinal plane.

2. A sewing machine including a column bearing an arm, a needle-carrier and a thread-puller mounted at the end of said arm and actuated in a to-and-fro movement, a spool support located on the rear wall of said arm and a threadguide arranged at the end of said arm at the height of said spool support, a part protruding with respect to the end face of said arm dis posed for safeguarding the full length of the thread path located between said guide and said thread-puller which merges laterally from said protruding part on the front of said arm, a tension device for the thread covered by said protruding part, a shaft for said tension device having its axis located in a longitudinal middle plane of said arm, said protruding part having front and rear walls and being of the general shape of a V of which the lower angle is rounded, and guiding elements for the thread at the entrance and at the exit of said tension device located in the front and rear walls of said V-shaped protruding part.

3. A sewing machine including a column hearing an arm, a needle-carrier and a thread-puller mounted at the end of said arm and actuated in a to-and-fro movement, a spool support located on the rear wall of said arm and a threadguide arranged at the end of said arm at the height of said spool support, a part protruding with respect to the end face of said arm disposed for safeguarding the full length of the thread path located between said guide and said thread-puller which merges laterally from said protruding part on the front of said arm, said thread-guide and the end of said thread-puller in its extreme position being situated almost in a same horizontal plane and on either side and approximately at an even distance from a longitudinal middle plane of said arm, a tension device for the thread covered by said protruding part, a shaft for said tension device having its axis located in said longitudinal plane of said arm, said protruding part having front and rear walls and being of the general shape of a V of which the lower angle is rounded, guiding elements for the thread at the entrance and at the exit of said tension device located in the front and rear walls of said V-shaped protruding part, whereby the part of the thread path between said thread-guide and said entrance guiding element as well as the part of the thread path between said exit guiding element and the end of said thread-puller, in its upper position, are both situated in an angle formed by the front and rear walls of the V-shaped walls protruding part on the one hand and by said end of said arm on the other hand,

4. A sewing machine including a column hearing an arm, a needle-carrier and a thread-puller mounted at the end of said arm and actuated in a to-and-fro movement, a spool support located on the rear wall of said arm and a threadguide arranged at the end of said arm at the height of said spool support, a part protruding with respect to the end face of said arm disposed for safeguarding the full length of the thread path located between said guide and said thread=puller which merges laterally from said protruding part on the front of said arm, said thread-guide and the end of said thread-puller in its extreme position being situated almost in a same horizontal plane and on either side and approximately at an even distance from a longitudinal middle plane of said arm, a tension device for the thread covered by said protrudin part, a shaft for said tension device having an axis located in said longitudinal plane of said arm, said protruding part having front and rear walls and being of the general shape of a V of which the lower angle is rounded, said front and rear walls of said V-shaped protruding part being connected by a bottom wall, having the shape of a semi-cylinder of approximately the same radius and the same center as the said tension device, and a slot in said semi-cylindrical wall located in the plane of the thread path for the passage of said thread.

5. A sewing machine including a column bearing an arm, a needle-carrier and a thread-puller mounted at the end of said arm and actuated in a to-and-fro movement, a spool support located on-the rear wall of said arm and a threadguide arranged at the end of said arm at the height of said spool support, a part protruding with respect to the end face of said arm disposed for safeguarding the full length of the thread path located between said guide and said thread-puller which merges laterally from said protruding part on the front of said arm, said thread-guide and the end of said thread-puller in its extreme position being situated almost in a same horizontal plane and on either side and approximately at an even distance from a longitudinal middle plane of said arm, atension device for the thread covered by said protruding part, a shaft for said tension device having an axis located in said longitudinal plane of said arm, said protruding part having front and rear Walls and being of the general shape of a V of which the lower angle is rounded,v guiding elements for the thread at the entrance and at the exit of said tension device located in the front and rear walls of said V-shaped protruding part, said front and rear walls of said V-shaped protruding part being connected by a bottom wall, having the shape of a semi-cylinder of approximately the same radius and the same center as the said tension device, and, a slot in said semi-cylindrical wall extending up to the height of said entrance and exit guiding elements of said tension device.

RAMON CASAS ROBERT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 195,439 Bocher Sept. 25, 1877 386,300 Dial July 17, 1888 2,226,689 Barber Dec. 31, 1940 FOREIGN PATENTS Number Country Date 104,820 Australia Aug. 16, 1938 

